package com.sunxung.shiro;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.apache.shiro.authc.*;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.sunxung.database.UserBean;
import com.sunxung.database.UserService;
import com.sunxung.util.JWTUtil;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

@Service
public class MyRealm extends AuthorizingRealm {

	private static final Logger LOGGER = LogManager.getLogger(MyRealm.class);

	private UserService userService;

	@Autowired
	public void setUserService(UserService userService) {
		this.userService = userService;
	}

	/**
	 * 大坑！，必须重写此方法，不然Shiro会报错
	 */
	@Override
	public boolean supports(AuthenticationToken token) {
		return token instanceof JWTToken;
	}

	/**
	 * 只有当需要检测用户权限的时候才会调用此方法，例如checkRole,checkPermission之类的
	 */
	@Override
	protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
		String username = JWTUtil.getUsername(principals.toString());
		UserBean user = userService.getUser(username);
		SimpleAuthorizationInfo simpleAuthorizationInfo = new SimpleAuthorizationInfo();
		simpleAuthorizationInfo.addRole(user.getRole());
		Set<String> permission = new HashSet<>(Arrays.asList(user.getPermission().split(",")));
		simpleAuthorizationInfo.addStringPermissions(permission);
		return simpleAuthorizationInfo;
	}

	/**
	 * 默认使用此方法进行用户名正确与否验证，错误抛出异常即可。
	 */
	@Override
	protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken auth) throws AuthenticationException {
		String token = (String) auth.getCredentials();
		// 解密获得username，用于和数据库进行对比
		String username = JWTUtil.getUsername(token);
		if (username == null) {
			throw new AuthenticationException("token invalid");
		}

		UserBean userBean = userService.getUser(username);
		if (userBean == null) {
			throw new AuthenticationException("User didn't existed!");
		}

		if (!JWTUtil.verify(token, username, userBean.getPassword())) {
			throw new AuthenticationException("Username or password error");
		}

		return new SimpleAuthenticationInfo(token, token, "my_realm");
	}
}
